Although Yazdegerd was at first tolerant of the Christians, he remained a zealous Zoroastrian and later persecuted both Christians and Jews. He was engaged in a short war with Rome in 442 and also fought against the Kushans (Kuṣāṇas) and Kidarites in the east. Little else is known of Yazdegerd’s reign; he was succeeded in turn by two of his sons, Hormizd III and Fīrūz.